Robust layered 3:2 pulldown film mode source detection

Abstract

A robust layered 3:2 pulldown film mode source detection method is proposed. The method provides video signals of three fields, a current field, a last field and a next field. The video signals are used to determine a film source. The method comprises steps of: define a plurality of layers and each layer has a threshold and a counter; compare each difference between pixels of the last field and the next field with each layer's threshold to obtain a comparing result; according to said comparing result, determine a change of said counter of each layer; and determine a result sequence by said counter to decide said film mode source.

What is claimed is:  
     
         1 . A method for robust layered 3:2 pulldown film mode source detection, said method providing video signals of three fields, a current field, a last field and a next field, said video signals being used to determine a film source and said method comprising steps of: 
 defining a plurality of layers and each layer has a threshold and a counter;    comparing each difference between pixels of said last field and said next field with each layer's threshold to obtain a comparing result;    according to said comparing result, determining a change of said counter of every layer; and    determining a result sequence by said counter to decide said film mode source.    
     
     
         2 . The method according to  claim 1  wherein said layers are three.  
     
     
         3 . The method according to  claim 1  wherein said counter of a layer is increased by 1 when the absolute value of each difference is bigger than a threshold of a layer.  
     
     
         4 . The method according to  claim 1  wherein said result sequence uses the fame difference of the film source processed by 3:2 pulldown as the fixed sequence by its counter.